[1] The third named storm of the 1961 Atlantic hurricane season, Carla developed from an area of squally weather in the southwestern Caribbean Sea on September 3.

[2] Carla made landfall at 2 p.m. on September 11 near Port O'Connor, Texas as a category 4 hurricane with a peak intensity of 145 mph (125 knots).

As early as September 1, a tropical disturbance – an area of convective activity – was observed tracking westward across the Caribbean Sea within the Intertropical Convergence Zone (ITCZ).

The Weather Bureau Office in Miami, Florida issued its first bulletin at 1600 UTC on September 4, while the depression was centered about 250 miles (400 km) east-southeast of Cabo Gracias a Dios, Nicaragua.

[3] It is estimated that sustained winds reached 45 mph (72 km/h) at 1200 UTC on September 5,[5] thus the depression strengthened into a tropical storm and was named Carla, while located just northeast of Cabo Gracias a Dios.

Radars reported an unusually large tropical cyclone, with convective bands extending about 520 miles (840 km) outward from the center.

Around 0000 UTC on September 6, Carla passed near Swan Island, which reported a barometric pressure of about 995 mbar (29.4 inHg) and wind gusts of 60 mph (97 km/h) from the southwest.

[5] Based on observations obtained by a reconnaissance aircraft at 1100 UTC on September 6 – namely a barometric pressure of 982 mbar (29.0 inHg) – a bulletin issued by the Weather Bureau an hour later indicated that the storm had "probably reached hurricane intensity".

Carla was upgraded to a Category 4 hurricane early on September 10, while approaching the Gulf Coast of the United States.

Operationally, at 0000 UTC on September 11, Carla strengthened into a Category 5 hurricane while located in the northwestern Gulf of Mexico.

[4] However, a 2018 reanalysis concluded that Carla did not reach Category 5 intensity, and in fact only had maximum sustained winds of 145 mph (233 km/h), and this has been officially incorporated into HURDAT.

Later that day, the storm struck Matagorda Island, Texas (seven miles south of Port O'Connor) with winds of 145 mph (233 km/h).

Carla rapidly weakened inland, and degenerated to a Category 2 hurricane on September 12, while passing just east of Port Lavaca.

After reaching Oklahoma early on September 13, Carla transitioned into an extratropical cyclone while located over rural Johnston County.

The extratropical remnants of Carla moved rapidly northeastward and brought heavy rainfall to some areas of the Great Plains and Midwestern United States.

[4] Occurring a year after Hurricane Donna, officials in the Florida Keys took precautions to brace for potential impact from the storm.

[11] An estimated 500,000 people fled the coasts of Texas and Louisiana, making it the largest evacuation in the history of the United States, at the time.

[16][17][18] Abnormally high tides and storm surge was reported along the coast of Texas, reaching at least 10 feet (3.0 m) above mean sea level at many coastal areas between Sabine Pass and Port Aransas.

Rather also alerted the public of the size of Carla in a way that "literally changed the way the world sees hurricanes", according to a fellow reporter.

Broadcasting live at the Weather Bureau Office in Galveston, Rather asked a meteorologist to outline the Gulf of Mexico on a transparent sheet of plastic.

Additionally, water inundation washed out several bridges and highways in northeastern parts of the state, leaving roads impassable.

Winds and rain combined severely disrupted electrical and telephone services and caused $670,000 in damage, with $600,000 to property and $70,000 to crops.

After the Chicago River rose 5 feet (1.5 m), the lock gate to Lake Michigan was opened to release excess water.

[16] In Nebraska, rainfall peaked at 5.68 inches (144 mm) in Hubbrell, making Carla the rainiest tropical cyclone in the state.

Rainfall in Iowa peaked at 9.03 inches (229 mm) near Chariton, making Carla the rainiest tropical cyclone in the state.

[16] Precipitation in Wisconsin reached 7.58 inches (193 mm) in Brodhead, causing Carla to rank as the wettest tropical cyclone in the state.

[28] In Cuba, broadcasts reported severe flooding near Pinar del Río, and in Los Colomas and Punta de Cartas.

Offshore Honduras on Swan Island, a rainfall amount of 3.89 inches (99 mm) was reported along with wind gusts up to 60 mph (97 km/h).

[33] President Kennedy issued a disaster declaration for Texas, allowing all jurisdictions in the state to apply for public assistance.

Members of the United States National Guard assisted refugees in returning to their homes and worked to prevent looting.